The present invention relates to a heat-processible color photographic material, in particular, a heat-processible color photographic material of diffusion transfer type which contains a novel dye providing-material.
Heat-processible photographic materials which provide image in a simple and quick way through development conducted by a thermal dry process have been known and these materials as well as methods for forming image thereon are described in the literature including JP-B-43-4921 (the term "JP-B" as used herein means an "examined Japanese patent publication"), JP-B-43-4921, "Shashin Kogaku no Kiso (Fundamentals of Photographic Engineering)", Part I, Silver Photography, pp. 553-555, Corona-sha, 1979, and Research Disclosure (RD-17029), pp. 9-15, June, 1978.
Heat-processible photographic materials are available In two types, one intended to produce black-and-white image and the other for producing color image, and active efforts are being made today to design heat-processible photographic materials of the first type which produce color image using a variety of dye-providing materials.
In actual applications, heat-processible color photographic materials work in various ways and those which produce color image by transferring the diffusible dye released or formed upon thermal development (this process is hereinafter referred to as a "transfer process") are advantageous in many respects including image stability and sharpness, as well as ease and rapidity with which photographic processing can be achieved. Heat-processible color photographic materials that depend on this transfer process and methods of forming image by this process are described in the specifications of many patents such as JP-A-59-12431 (the term "JP-A" as used herein means as "unexamined published Japanese patent application"), JP-A-59-159159, JP-A-59-181345, JP-A-59-229556, JP-A-60-2950, JP-A-61-52643, JP-A-61-61158, JP-A-61-61157, JP-A-59-180550, JP-A-61-132952, JP-A-61-139842, and U.S. Pat. Nos. 4,595,652, 4,590,154 and 4,584,267.
Image formation on these heat-processible photographic materials of transfer type involves the steps of silver development, color formation and transfer but the respective steps are incapable of achieving an efficiency of 100%. Thus, in order to produce image of high density, not only the silver content but also the amounts of additives such as reducing agent and dye-providing materials must be increased. This problem could be solved by improving the efficiency of individual steps involved in photographic processing but considerable difficulty is encountered in increasing the efficiency of each step to nearly 100%. Furthermore, this approach causes other problems such as increased fog.
The present invention has been accomplished in order to solve these problems of the prior art and eliminate the defects inherent in the conventional heat-processible color photographic materials of transfer type.